/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.action.admin.cluster.snapshots;

import org.opensearch.action.admin.cluster.repositories.verify.VerifyRepositoryResponse;
import org.opensearch.action.admin.cluster.snapshots.create.CreateSnapshotResponse;
import org.opensearch.action.admin.cluster.snapshots.get.GetSnapshotsResponse;
import org.opensearch.action.admin.cluster.snapshots.restore.RestoreSnapshotResponse;
import org.opensearch.action.admin.cluster.snapshots.status.SnapshotsStatusResponse;

import org.opensearch.cluster.metadata.Metadata;
import org.opensearch.common.settings.Settings;
import org.opensearch.rest.RestStatus;
import org.opensearch.test.OpenSearchIntegTestCase;
import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;

import org.junit.Before;

import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_BLOCKS_READ;
import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_READ_ONLY;
import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertBlocked;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.hasSize;

/**
 * This class tests that snapshot operations (Create, Delete, Restore) are blocked when the cluster is read-only.
 *
 * The @NodeScope TEST is needed because this class updates the cluster setting "cluster.blocks.read_only".
 */
@ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST)
public class SnapshotBlocksIT extends OpenSearchIntegTestCase {

    protected static final String INDEX_NAME = "test-blocks-1";
    protected static final String OTHER_INDEX_NAME = "test-blocks-2";
    protected static final String COMMON_INDEX_NAME_MASK = "test-blocks-*";
    protected static final String REPOSITORY_NAME = "repo-" + INDEX_NAME;
    protected static final String SNAPSHOT_NAME = "snapshot-0";

    @Before
    protected void setUpRepository() throws Exception {
        createIndex(INDEX_NAME, OTHER_INDEX_NAME);

        int docs = between(10, 100);
        for (int i = 0; i < docs; i++) {
            client().prepareIndex(INDEX_NAME).setSource("test", "init").execute().actionGet();
        }
        docs = between(10, 100);
        for (int i = 0; i < docs; i++) {
            client().prepareIndex(OTHER_INDEX_NAME).setSource("test", "init").execute().actionGet();
        }

        logger.info("--> register a repository");

        assertAcked(
            client().admin()
                .cluster()
                .preparePutRepository(REPOSITORY_NAME)
                .setType("fs")
                .setSettings(Settings.builder().put("location", randomRepoPath()))
        );

        logger.info("--> verify the repository");
        VerifyRepositoryResponse verifyResponse = client().admin().cluster().prepareVerifyRepository(REPOSITORY_NAME).get();
        assertThat(verifyResponse.getNodes().size(), equalTo(cluster().numDataAndClusterManagerNodes()));

        logger.info("--> create a snapshot");
        CreateSnapshotResponse snapshotResponse = client().admin()
            .cluster()
            .prepareCreateSnapshot(REPOSITORY_NAME, SNAPSHOT_NAME)
            .setIncludeGlobalState(true)
            .setWaitForCompletion(true)
            .execute()
            .actionGet();
        assertThat(snapshotResponse.status(), equalTo(RestStatus.OK));
        ensureSearchable();
    }

    public void testCreateSnapshotWithBlocks() {
        logger.info("-->  creating a snapshot is allowed when the cluster is read only");
        try {
            setClusterReadOnly(true);
            assertThat(
                client().admin().cluster().prepareCreateSnapshot(REPOSITORY_NAME, "snapshot-1").setWaitForCompletion(true).get().status(),
                equalTo(RestStatus.OK)
            );
        } finally {
            setClusterReadOnly(false);
        }

        logger.info("-->  creating a snapshot is allowed when the cluster is not read only");
        CreateSnapshotResponse response = client().admin()
            .cluster()
            .prepareCreateSnapshot(REPOSITORY_NAME, "snapshot-2")
            .setWaitForCompletion(true)
            .execute()
            .actionGet();
        assertThat(response.status(), equalTo(RestStatus.OK));
    }

    public void testCreateSnapshotWithIndexBlocks() {
        logger.info("-->  creating a snapshot is not blocked when an index is read only");
        try {
            enableIndexBlock(INDEX_NAME, SETTING_READ_ONLY);
            assertThat(
                client().admin()
                    .cluster()
                    .prepareCreateSnapshot(REPOSITORY_NAME, "snapshot-1")
                    .setIndices(COMMON_INDEX_NAME_MASK)
                    .setWaitForCompletion(true)
                    .get()
                    .status(),
                equalTo(RestStatus.OK)
            );
        } finally {
            disableIndexBlock(INDEX_NAME, SETTING_READ_ONLY);
        }

        logger.info("-->  creating a snapshot is blocked when an index is blocked for reads");
        try {
            enableIndexBlock(INDEX_NAME, SETTING_BLOCKS_READ);
            assertThat(
                client().admin()
                    .cluster()
                    .prepareCreateSnapshot(REPOSITORY_NAME, "snapshot-2")
                    .setIndices(COMMON_INDEX_NAME_MASK)
                    .setWaitForCompletion(true)
                    .get()
                    .status(),
                equalTo(RestStatus.OK)
            );
        } finally {
            disableIndexBlock(INDEX_NAME, SETTING_BLOCKS_READ);
        }
    }

    public void testDeleteSnapshotWithBlocks() {
        logger.info("-->  deleting a snapshot is allowed when the cluster is read only");
        try {
            setClusterReadOnly(true);
            assertTrue(client().admin().cluster().prepareDeleteSnapshot(REPOSITORY_NAME, SNAPSHOT_NAME).get().isAcknowledged());
        } finally {
            setClusterReadOnly(false);
        }
    }

    public void testRestoreSnapshotWithBlocks() {
        assertAcked(client().admin().indices().prepareDelete(INDEX_NAME, OTHER_INDEX_NAME));
        assertFalse(client().admin().indices().prepareExists(INDEX_NAME, OTHER_INDEX_NAME).get().isExists());

        logger.info("-->  restoring a snapshot is blocked when the cluster is read only");
        try {
            setClusterReadOnly(true);
            assertBlocked(
                client().admin().cluster().prepareRestoreSnapshot(REPOSITORY_NAME, SNAPSHOT_NAME),
                Metadata.CLUSTER_READ_ONLY_BLOCK
            );
        } finally {
            setClusterReadOnly(false);
        }

        logger.info("-->  creating a snapshot is allowed when the cluster is not read only");
        RestoreSnapshotResponse response = client().admin()
            .cluster()
            .prepareRestoreSnapshot(REPOSITORY_NAME, SNAPSHOT_NAME)
            .setWaitForCompletion(true)
            .execute()
            .actionGet();
        assertThat(response.status(), equalTo(RestStatus.OK));
        assertTrue(client().admin().indices().prepareExists(INDEX_NAME).get().isExists());
        assertTrue(client().admin().indices().prepareExists(OTHER_INDEX_NAME).get().isExists());
    }

    public void testGetSnapshotWithBlocks() {
        // This test checks that the Get Snapshot operation is never blocked, even if the cluster is read only.
        try {
            setClusterReadOnly(true);
            GetSnapshotsResponse response = client().admin().cluster().prepareGetSnapshots(REPOSITORY_NAME).execute().actionGet();
            assertThat(response.getSnapshots(), hasSize(1));
            assertThat(response.getSnapshots().get(0).snapshotId().getName(), equalTo(SNAPSHOT_NAME));
        } finally {
            setClusterReadOnly(false);
        }
    }

    public void testSnapshotStatusWithBlocks() {
        // This test checks that the Snapshot Status operation is never blocked, even if the cluster is read only.
        try {
            setClusterReadOnly(true);
            SnapshotsStatusResponse response = client().admin()
                .cluster()
                .prepareSnapshotStatus(REPOSITORY_NAME)
                .setSnapshots(SNAPSHOT_NAME)
                .execute()
                .actionGet();
            assertThat(response.getSnapshots(), hasSize(1));
            assertThat(response.getSnapshots().get(0).getState().completed(), equalTo(true));
        } finally {
            setClusterReadOnly(false);
        }
    }
}
